Cleaning tunnel tubes... Options

[SKL1]

In troubleshooting a binding throttle cable, after removing the old cable I was trying to fish the new Terry cable thru the tunnel tube and it kept getting caught up about 2 1/2- 3 feet in towards the front. Could fish a stiff wire through fine but the bigger threaded end would not go past that point. Could also get the old cable end back thru but the new one must be slightly bigger diameter and will NOT go. Looking thru the little holes by the shifter and heater lever (which is removed anyway as I'm not using a heater) I can't really see the tubes anyway so can't see from the front if something is partially blocking it.
I remember helping my son clean the SAI ports on his 993 with an old bicycle brake cable and a power drill and wondered if I fish something like that through it may clean something out left from the restoration and painting. Since I'm not using tubes from the heater cables I thought about using one of those but the flared ends don't fit the throttle cable end that well.

Any ideas of what to use on a drill etc to "clean" things out?? I don't want to destroy another cable trying to "force" it through...

This throttle linkage project is going to be the end of me... (IMG:style_emoticons/default/headbang.gif)